The following databases will be helpful for locating journal articles on your topic:
MLA International Bibliography
Literature Online (LION)
Bibliography of British and Irish History
Cambridge Histories Online (good for histories of the British theatre)
International Medieval Bibliography
Iter: Gateway to the Middle Ages and Renaissance
Medieval Travel Writing
*note: JSTOR is not a bad place to start. It has a great interface and it is easy to access full texts of articles. But it also does not have the same coverage as other databases. I highly encourage you to try some of the other tools listed.
Subject Headings (for books)
RACER is an online Interlibrary Loan system used to search for material and place requests. To access RACER you must have an account. To create your account, you need to register. If you have already registered, simply login. Please keep in mind that your University ID number is used as your login and your password is created by you.